Jump to

This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.

Abstract

Background—The Fick principle (cardiac output = oxygen uptake (O2)/systemic arterio-venous oxygen difference) is used to determine cardiac output in numerous clinical situations. However, estimated rather than measured O2 is commonly used because of complexities of the measurement, though the accuracy of estimation remains uncertain in contemporary clinical practice.

Conclusions—Estimates of resting O2 derived from conventional formulae are inaccurate, especially in severely obese individuals. When accurate hemodynamic assessment is important for clinical decision-making, O2 should be directly measured.